Is BMI still a good way of looking at body weight?

In a recent study researchers pulled data on over 40,000 people and analyzed the link between BMI

(body mass index – the ratio between body weight and height) and key health markers such as

Blood pressure

Glucose levels

Insulin resistance

Cholesterol & Glyceride levels

What they found is that the BMI didn’t fit with the findings, as a matter of fact they were way off.

For example, the researchers found that nearly half of overweight men and women and 29% of obese people were otherwise completely healthy. And the opposite was also true.. 30% of people with “normal” BMI’s were unhealthy according to the markers.

That means that there are tens of millions of people who are overweight and obese and perfectly healthy says author A. Janet Tomiyama PhD, asst professor of psychology at UCLA.

This data can be relevant for active, fit people like runners, walkers and cyclists who have optimal BMI’s but may have poor markers.

Active people tend to have more muscle tissue, which is denser than fat tissue and can therefore alter the BMI. In addition, BMI doesn’t tell us where and how body fat is distributed. For example, in two people with the same BMI one can have it as belly fat (or visceral fat) which is known to be a higher health risk, while the other person may store the fat as subcutaneous fat just under the skin in various parts of the body, which is not a health risk.

Dr. Tomiyama further stated that “in our study we used a very stringent and comprehensive definition of health that included blood pressure, triglycerides, “good & bad” cholesterol, blood sugar, and inflammation”, noting that these tests are far better indicators of health than BMI alone.